Who Gives A Fish Forums

I've had my blonde naso for about a month now and just started noticing these brown/black spots on him the past few days. There's also some lines of this brown/black stuff on him.

Here are some pics:

You'll see some spots on the glass, but check around his mouth, eye, and under the Sprig - that's where the spots are.

And again, you can see the spots just before the tail starts.

Anyone have an idea what's going on?

When nasos get stressed or are sleeping, they can get these blotchy brown and white marks. If your fish is still eating and acting fine, I'd just leave him be for now.

zenoxa wrote: ↑Sun Mar 23, 2025 5:47 am When nasos get stressed or are sleeping, they can get these blotchy brown and white marks. If your fish is still eating and acting fine, I'd just leave him be for now.

Yeah, I agree with that. Also, make sure to vary his diet and feed him often. Meaty foods, spirulina-enriched stuff, and some seaweed will do him good.

I've also heard that adding garlic can give them a bit of a boost to their immune system.

Honestly, it doesn't cure anything. But I've found that garlic does seem to have a positive effect on my fish's health. The exact reason is still unclear, but it's possible that it makes their flesh unappealing to parasites. I've seen it work wonders for my domino damsel.

Feeding garlic and spirulina-enriched foods is a great way to combat small infestations. Spirulina is one of the healthiest foods out there, in my experience.

I'm really worried about my blonde naso, I think he's in trouble. The brown spots have gone but now he just lies on the sand and then suddenly starts thrashing about, swimming upside down and bumping into my rocks. What's going on with him?

Sounds like your fish is in a pretty rough state. I'm worried it might be dealing with ammonia or nitrite poisoning, but parasites are a more likely culprit. To be honest, I've only seen one fish recover from something like this - a freshwater Pangasius that I immediately moved to a clean environment after it was exposed to ammonia-laden water.

We totally dropped the ball, what's your water parameters like, flier_kit?

zenoxa wrote: ↑Sun Mar 23, 2025 5:47 am When nasos get stressed or are sleeping, they can get these blotchy brown and white marks. If your fish is still eating and acting fine, I'd just leave him be for now.

I was thinking, wouldn't that be related to the immune system in some way?

I think it's more that constant feeding of garlic-infused foods could potentially weaken the immune system over time, similar to how overusing antibiotics or hand sanitizers can have a negative impact on our own immune systems.